Unit and method of feeding containers arranged in a number of superimposed rows

ABSTRACT

A unit and method for feeding containers, whereby the containers, arranged in two superimposed rows, are fed along a horizontal path and through a reject station; upstream from the reject station, two superimposed containers are parted, by translation in a vertical direction, so as to travel, separately and facing each other, along the next portion of the path; immediately downstream from the reject station, two facing containers are brought back into contact with each other so as to travel, superimposed, along the next portion of the path; and the reject station has a first reject device for expelling only one container in a bottom row from the path, and a second reject device for expelling only one container in a top row from the path.

The present invention relates to a unit and method of feeding containersarranged in a number of superimposed rows.

The present invention may be used to particular advantage on a cigarettepacking line, to which the following description refers purely by way ofexample.

BACKGROUND OF THE INVENTION

A cigarette packing line normally comprises a manufacturing machine forproducing the cigarettes; a filter assembly machine for applying filtersto the cigarettes; a packing machine for producing soft or rigid packetsof cigarettes; a cellophaning machine for applying an overwrapping oftransparent plastic material to the packets of cigarettes; and acartoning machine for producing cartons of packets of cigarettes.

A feed unit is interposed between the cellophaning machine and thecartoning machine to receive a succession of packets of cigarettes froman output of the cellophaning machine and transfer the succession ofpackets of cigarettes to an input of the cartoning machine. The feedunit often has a reject station located along the path of the packets ofcigarettes to remove from the path any faulty packets of cigarettesdetected by control stations on the cellophaning machine. Location ofthe reject station at the feed unit is usually advantageous on accountof the considerable size of the reject station, which must also collectthe rejected packets of cigarettes and is difficult to accommodate onthe cellophaning machine.

Some known packing lines of the type described above are designed totransfer from the output of the cellophaning machine to the input of thecartoning machine a succession of packets of cigarettes arranged in twoor more superimposed rows, so as to reduce the average travelling speed,and hence mechanical stress, of the packets of cigarettes.

When feeding packets of cigarettes arranged in two or more superimposedrows, rejection of a faulty packet of cigarettes travelling through thereject station calls for also rejecting the good packet/s stacked withit. This is due to the way in which known reject stations are built andoperate, which does not permit removal from the stream of a singlepacket stacked with another.

The feed unit may also comprise a heat-shrink station for heat treatingeach packet of cigarettes. For each row of packets of cigarettes, theheat-shrink station comprises a respective channel, along which the rowof packets of cigarettes travels in use, and which is bounded at the topand bottom by two slide surfaces equipped with electric heatingelements. When a packet of cigarettes is pushed along the respectivechannel at the heat-shrink station, the major lateral walls of thepacket of cigarettes inevitably slide along the heated slide surfaces,thus generating friction on the packet of cigarettes, which is afunction of the pressure exerted on the packet by the slide surfaces. Toavoid subjecting the packet of cigarettes to severe friction which mightdamage or even tear the sheet of overwrapping material, the slidesurfaces are spaced far apart. Such a solution, however, reduces theeffectiveness of the heat treatment and calls for using very longheat-shrink stations.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a unit and method offeeding containers arranged in a number of superimposed rows, which unitand method are designed to eliminate the aforementioned drawbacks and,in particular, are cheap and easy to implement.

According to the present invention, there are provided a unit and methodof feeding containers arranged in a number of superimposed rows, asclaimed in the accompanying claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A non-limiting embodiment of the present invention will be described byway of example with reference to the accompanying drawings, in which:

FIG. 1 shows a schematic plan view, with parts removed for clarity, of afeed unit in accordance with the present invention and located betweenan output of a cellophaning machine and the input of a cartoningmachine;

FIG. 2 shows a schematic lateral section of part of the FIG. 1 feedunit;

FIGS. 3 to 5 show schematic lateral sections of three instants in theoperation of a parting station of the FIG. 1 feed unit;

FIG. 6 shows a schematic plan view of a rotation station of the FIG. 1feed unit.

DETAILED DESCRIPTION OF THE INVENTION

Number 1 in FIG. 1 indicates as a whole a feed unit for feedingcontainers or packets 2 of cigarettes arranged in two superimposed,respectively bottom and top, rows 3 and 4. Feed unit 1 forms part of acigarette packing line comprising a cellophaning machine 5 for applyingan overwrapping of transparent plastic material to packets 2 ofcigarettes; and a cartoning machine 6 for producing cartons of packets 2of cigarettes. More specifically, feed unit 1 is interposed betweencellophaning machine 5 and cartoning machine 6, receives a succession ofpackets 2 of cigarettes from an output 7 of cellophaning machine 5, andtransfers the succession of packets 2 of cigarettes to an input 8 ofcartoning machine 6.

Feed unit 1 comprises a conveying device 9 for feeding packets 2 along ahorizontal U-shaped path P extending from output 7 of cellophaningmachine 5 to input 8 of cartoning machine 6. More specifically, path Pcomprises a linear start portion P1; a linear intermediate portion P2perpendicular to start portion P1; and a linear end portion P3 parallelto start portion P1.

Conveying device 9 comprises a U-shaped slide surface 10 parallel topath P and for supporting packets 2 in sliding manner; and a push device11 for pushing packets 2 along slide surface 10. Push device 11comprises a pusher 12 having a number of push members 13 fitted to anendless belt 14 (shown only partly), and which pushes packets 2 alongstart portion P1; a pusher 15 having a 16 with a linear reciprocatingmovement, and which pushes packets 2 along intermediate portion P2; anda pusher 17 having a number of push members 18 fitted to an endless belt19, and which pushes packets 2 along end portion P3.

As shown in FIG. 2, a heat-shrink station S1, for heat treating eachpacket 2, and a reject station S2, for expelling any faulty packets 2from path P, are arranged in succession along intermediate portion P2 ofpath P.

Upstream from heat-shrink station S1, and therefore upstream from rejectstation S2, is located a parting station S3 where two superimposedpackets 2 are parted by translation in a vertical direction Dperpendicular to path P, so as to travel separately and facing eachother along the next portion of path P. Immediately downstream fromreject station S2, and therefore downstream from heat-shrink station S1,is located a stacking station S4 where two facing packets 2 are broughtback into contact with each other by translation in a vertical directionD, so as to travel, superimposed, along the next portion of path P.

In other words, rows 3 and 4 of packets 2 travel, superimposed, alongpath P with the exception of the portion of intermediate portion P2 ofpath P extending between parting station S3 and stacking station S4;along which portion, rows 3 and 4 of packets 2 are fed parted and facingeach other by conveying device 9, and in particular pusher 15.

Heat-shrink station S1 comprises a further two slide surfaces 20 and 21,which are parallel to and face slide surface 10 to define, with slidesurface 10, two channels 22 and 23, along which respective rows 3 and 4of packets 2 are fed. More specifically, the bottom row 3 of packetsslides along slide surface 10 and inside channel 22 defined betweenslide surface 10 and slide surface 20, while the top row 4 of packetsslides along slide surface 20 and inside channel 23 defined betweenslide surface 20 and slide surface 21.

Slide surfaces 10, 20, 21 comprise electric heating elements (notshown), which are embedded inside slide surfaces 10, 20, 21 andcontrolled to heat channels 22, 23 to a given temperature, whichnormally depends on the travelling speed of packets 2 along path P, andon the type of plastic overwrapping material (not shown) applied topackets 2.

In a preferred embodiment, slide surfaces 10 and 21 at heat-shrinkstation S1 are movable in a vertical direction D perpendicular to pathP, and heat-shrink station S1 comprises two actuating devices 24 formoving slide surfaces 10 and 21 cyclically in vertical direction Dperpendicular to path P, so as to move slide surfaces 10 and 21cyclically towards and away from slide surface 20. In a preferredembodiment, both actuating devices 24 form part of the same mechanism,i.e. are powered by a common motor. In an alternative embodiment, thetwo actuating devices 24 are mechanically independent.

More specifically, conveying device 9 feeds packets 2 along path P withan intermittent movement comprising a cyclic succession of travellingsteps and hold steps. And actuating devices 24 are timed with conveyingdevice 9 to keep slide surfaces 10 and 21 close to slide surface 20during the hold steps, and away from slide surface 20 during thetravelling steps in the intermittent movement. This has the dual effectof permitting unimpeded travel of packets 2 along path P, and increasingheat transmission to packets 2 by virtue of sliding surfaces 10, 20, 21firmly contacting packets 2.

The actual size of packets 2 varies fairly widely on account ofinevitable tolerances as regards both materials and packing processes.Between each actuating device 24 and respective slide surface 10, 21, anelastic member 24 a is therefore preferably interposed to allow acertain amount of flexible self-adjustment of the position of slidesurface 10, 21 in vertical direction D. This is particularly useful byenabling slide surfaces 10 and 21 to adapt automatically to the actualsize of packets 2.

In other words, by means of elastic members 24 a, substantially constantpressure is applied on each packet 2 regardless of the actual size ofpacket 2.

By way of example, each elastic member 24 a interposed between eachactuating device 24 and respective slide surface 10, 21 is defined by aspring, a pneumatic shock absorber, or an elastomer.

Reject station S2 comprises a reject device 25 for only expelling onebottom packet 2, i.e. in bottom row 3 of packets 2, from path P; and areject device 26 for only expelling one top packet 2, i.e. in top row 4of packets 2, from path P. Each reject device 25, 26 preferablycomprises a pneumatic push device (not shown in detail) for pushing apacket 2 off path P in a horizontal direction perpendicular to path P.

Slide surface 20 ends at stacking station S4, so that the packets 2 intop row 4 travelling along slide surface 20 are eventually unsupportedfrom underneath and drop by force of gravity onto packets 2 in bottomrow 3. In the event a packet 2 in bottom row 3 is expelled at rejectstation S2, the corresponding packet 2 in top row 4 would have too farto fall at stacking station S4 and may become misaligned, so stackingstation S4 comprises a supporting surface 27 movable, in a verticaldirection D perpendicular to path P, between a withdrawn position, inwhich a top face of supporting surface 27 is aligned with a top face ofslide surface 10, and a raised position, in which the top face ofsupporting surface 27 is raised with respect to the top face of slidesurface 10.

When a packet 2 in bottom row 3 and a corresponding packet 2 in top row4 are both present, supporting surface 27 is maintained in the withdrawnposition, and, at the end of slide surface 20, packet 2 in top row 4drops a short distance vertically onto packet 2 in bottom row 3. Whenonly a packet 2 in top row 4 is present, with no corresponding packet 2in bottom row 3, supporting surface 27 is moved into the raised positionto break the free fall of packet 2 in top row 4 and guide packet 2 downin controlled manner as supporting surface 27 moves back down into thewithdrawn position.

Parting station S3 comprises a supporting surface 28 movable, in avertical direction D perpendicular to path P, between a withdrawnposition, in which a top face of supporting surface 28 is aligned with atop face of slide surface 10, and a raised position, in which the topface of supporting surface 28 is raised with respect to the top face ofslide surface 10 and aligned with a top face of slide surface 20.Parting station S3 also comprises a clamping device 29 alignedvertically with supporting surface 28 and for clamping a packet 2 in agiven vertical position slightly above slide surface 20. In oneembodiment, clamping device 29 comprises a suction member (not shown).In an alternative embodiment, clamping device 29 comprises a gripper(not shown) having two jaws movable in a direction crosswise to path Pand in opposition to elastic means.

In actual use, and as shown in FIGS. 3 to 5, when a packet 2 in bottomrow 3 and a corresponding packet 2 in top row 4 reach parting stationS3, supporting surface 28 is moved from the withdrawn to the raisedposition to lift both packet 2 in bottom row 3 and corresponding packet2 in top row 4 and bring packet 2 in top row 4 into contact withclamping device 29. At this point, packet 2 in top row 4 remains incontact with clamping device 29, and, as supporting surface 28 movesback down into the withdrawn position, is parted from packet 2 in bottomrow 3 (resting on supporting surface 28).

As shown in FIG. 1, a known filler station S5 is located downstream fromreject station S2 to transfer a number of packets 2 to conveying device9 to replace any packets 2 expelled at reject station S2. Filler stationS5 comprises a vertical hopper 30 containing a stack of superimposedpackets 2 and having an outlet located over conveying device 9.

As shown in FIG. 6, conveying device 9 preferably comprises a rotationstation S6 for rotating each packet 2 by 180° about a vertical axis 31perpendicular to path P. Rotation station S6 comprises a horizontalturntable 32 having four vertical members 33 projecting upwards fromturntable 32 and arranged to enclose packets 2.

Reject station S2 as described above has numerous advantages byenabling, even in the case of packets of cigarettes arranged in two ormore superimposed rows, rejection of either all or only one of thepackets in a given stack, regardless of the location of the rejectedpacket.

Heat-shrink station S1 as described above has numerous advantages bypermitting unimpeded travel of packets 2 along path P, while at the sametime increasing heat transmission to packets 2 by virtue of slidesurfaces 10, 20, 21 firmly contacting packets 2.

Given its numerous advantages, feed unit 1 as described above may alsobe used to advantage at other points along a cigarette packing line, oreven on other automatic machines for packing other than cigarettes (e.g.food products).

1) A unit for feeding containers arranged in a number of superimposedrows; the unit (1) comprises conveying means (9) for feeding thecontainers (2), arranged in at least two superimposed rows (3, 4), alonga horizontal path (P), and a reject station (S2) for expelling anyfaulty containers (2) from the path (P); and the unit (1) ischaracterized by comprising a parting station (S3) located upstream fromthe reject station (S2) and wherein two superimposed containers (2) areparted, by translation in a vertical direction (D) perpendicular to thepath (P), so as to travel separately and facing each other along thenext portion of the path (P); and a stacking station (S4) locateddownstream from the reject station (S2) and wherein two facingcontainers (2) are brought back into contact with each other so as totravel, superimposed, along the next portion of the path (P); theconveying means (9) feed the two rows (3, 4) of containers (2)separately and facing each other between the parting station (S3) andthe stacking station (S4); and the reject station (S2) comprises a firstreject device (25) for only expelling one container (2) in a bottom row(3) from the path (P), and a second reject device (26) for onlyexpelling one container (2) in a top row (4) from the path (P). 2) Aunit as claimed in claim 1, wherein the stacking station (S4) is locatedimmediately downstream from the reject station (S2). 3) A unit asclaimed in claim 1, wherein the conveying means (9) comprise a firstslide surface (10) parallel to the path (P) and for supporting thecontainers (2) in sliding manner, and a pusher (15) for pushing the tworows (3, 4) of containers (2) so that the containers (2) slide along thefirst slide surface (10); between the parting station (S3) and thestacking station (S4), the conveying means (9) comprise a second slidesurface (20) parallel to and facing the first slide surface (10), sothat a bottom row (3) of containers (2) slides along the first slidesurface (10), and a top row (4) of containers (2) slides along thesecond slide surface (20). 4) A unit as claimed in claim 3, wherein thesecond slide surface (20) ends at the stacking station (S4). 5) A unitas claimed in claim 4, wherein the stacking station (S4) comprises afirst supporting surface (27) movable, in a vertical direction (D)perpendicular to the path (P), between a withdrawn position wherein atop face of the first supporting surface (27) is aligned with a top faceof the first slide surface (10), and a raised position wherein the topface of the first supporting surface (27) is raised with respect to thetop face of the first slide surface (10). 6) A unit as claimed in claim3, wherein the parting station (S3) comprises a second supportingsurface (28) movable, in a vertical direction (D) perpendicular to thepath (P), between a withdrawn position wherein a top face of the secondsupporting surface (28) is aligned with a top face of the first slidesurface (10), and a raised position wherein the top face of the secondsupporting surface (28) is raised with respect to the top face of thefirst slide surface (10) and aligned with a top face of the second slidesurface (20). 7) A unit as claimed in claim 6, wherein the partingstation (S3) comprises a clamping device (29) aligned vertically withthe second supporting surface (28) and for clamping a container (2) in agiven vertical position slightly above the second slide surface (20). 8)A unit as claimed in claim 7, wherein the clamping device (29) comprisesa suction member. 9) A unit as claimed in claim 7, wherein the clampingdevice (29) comprises a gripper having two jaws movable in a directioncrosswise to the path (P) and in opposition to elastic means. 10) A unitas claimed in claim 1, wherein each reject device (25; 26) comprises apush device for pushing a container (2) in a horizontal directionperpendicular to the path (P). 11) A unit as claimed in claim 10,wherein each push device is a pneumatic push device. 12) A unit asclaimed in claim 1, wherein a heat-shrink station (S1) is locatedbetween the parting station (S3) and the stacking station (S4) to heattreat each container (2). 13) A unit as claimed in claim 12, wherein theheat-shrink station (S1) comprises a first slide surface (10) parallelto the path (P) and for supporting in sliding manner the containers (2)in a bottom row (3); a second slide surface (20) parallel to and facingthe first slide surface (10) and for supporting in sliding manner thecontainers (2) in a top row (4); and a third slide surface (21) parallelto and facing the second slide surface (20); a first heated channel(22), along which the bottom row (3) of containers (2) travels, isdefined between the first slide surface (10) and the second slidesurface (20); and a second heated channel (23), along which the top row(4) of containers (2) travels, is defined between the second slidesurface (20) and the third slide surface (21). 14) A unit as claimed inclaim 13, wherein the slide surfaces (10, 20, 21) comprise electricheating elements. 15) A unit as claimed in claim 13, wherein theheat-shrink station (S1) comprises an actuating device (24) for movingthe first and third slide surface (10, 21) cyclically in a verticaldirection (D) perpendicular to the path (P), so as to move the first andthird slide surface (10, 21) cyclically towards and away from the secondslide surface (20). 16) A unit as claimed in claim 15, wherein theconveying means (9) feed the containers (2) along the path (P) with anintermittent movement comprising a cyclic succession of travelling stepsand hold steps; and the actuating device (24) is timed with theconveying means (9) to keep the first and third slide surface (10, 21)close to the second slide surface (20) during the hold steps in theintermittent movement, and to keep the first and third slide surface(10, 21) away from the second slide surface (20) during the travellingsteps in the intermittent movement. 17) A unit as claimed in claim 1,wherein a filler station (S5) is located downstream from the rejectstation (S2) to transfer a number of containers (2) to the conveyingmeans (9) to replace any containers (2) expelled at the reject station(S2). 18) A unit as claimed in claim 17, wherein the filler station (S5)comprises a vertical hopper (30) containing a stack of superimposedcontainers (2) and having an outlet located over the conveying means(9). 19) A unit as claimed in claim 1, wherein the path (P) is U-shaped;and the conveying means (9) comprise a U-shaped slide surface (10)parallel to the path (P) and for supporting the containers (2) insliding manner, and push means (11) for pushing the containers (2) alongthe slide surface (10). 20) A unit as claimed in claim 19, wherein thepush means (11) comprise a first pusher (12) defined by a number of pushmembers (13) carried by an endless first belt (14); a second pusher (15)defined by a piston (16) with a linear reciprocating movement; and athird pusher (17) defined by a number of push members (18) carried by anendless second belt (19). 21) A unit as claimed in claim 1, wherein theconveying means (9) comprise a rotation station (S6) for rotating eachcontainer (2) by 180° about a vertical axis (31) perpendicular to thepath (P). 22) A unit as claimed in claim 21, wherein the rotationstation (S6) comprises a horizontal turntable (32) having four verticalmembers (33) projecting upwards from the turntable (32) and arranged toenclose the containers (2). 23) A unit for feeding containers arrangedin a number of superimposed rows; the unit (1) comprises conveying means(9) for feeding the containers (2), arranged in at least twosuperimposed rows (3, 4), along a horizontal path (P), and a heat-shrinkstation (S1) for heat treating each container (2); the heat-shrinkstation (S1) comprises a first slide surface (10) parallel to the path(P) and for supporting in sliding manner the containers (2) in a bottomrow (3), a second slide surface (20) parallel to and facing the firstslide surface (10) and for supporting in sliding manner the containers(2) in a top row (4), and a third slide surface (21) parallel to andfacing the second slide surface (20); a first heated channel (22), alongwhich the bottom row (3) of containers (2) travels, is defined betweenthe first slide surface (10) and the second slide surface (20); a secondheated channel (23), along which the top row (4) of containers (2)travels, is defined between the second slide surface (20) and the thirdslide surface (21); and the unit (1) is characterized by comprisingactuating means (24) for moving the first and third slide surface (10,21) cyclically in a vertical direction (D) perpendicular to the path(P), so as to move the first and third slide surface (10, 21) cyclicallytowards and away from the second slide surface (20). 24) A unit asclaimed in claim 23, wherein the conveying means (9) feed the containers(2) along the path (P) with an intermittent movement comprising a cyclicsuccession of travelling steps and hold steps; and the actuating means(24) are timed with the conveying means (9) to keep the first and thirdslide surface (10, 21) close to the second slide surface (20) during thehold steps in the intermittent movement, and to keep the first and thirdslide surface (10, 21) away from the second slide surface (20) duringthe travelling steps in the intermittent movement. 25) A unit as claimedin claim 23, wherein the slide surfaces comprise electric heatingelements. 26) A unit as claimed in claim 23, wherein respective elasticmembers (24 a) are interposed between the actuating means (24) and thefirst and third slide surface (10, 21) to permit elastic self-adjustmentof the position of the first and third slide surface (10, 21) in thevertical direction (D). 27) A unit for feeding containers arranged in atleast one row; the unit (1) comprises conveying means (9) for feedingthe containers (2) along a horizontal path (P), and a heat-shrinkstation (S1) for heat treating each container (2); the heat-shrinkstation (S1) comprises a first slide surface (10) parallel to the path(P) and for supporting the containers (2) in sliding manner, and asecond slide surface (20) parallel to and facing the first slide surface(10); a heated channel (22), along which the row (3) of containers (2)travels, is defined between the first slide surface (10) and the secondslide surface (20); an actuating device (24) is provided for moving thefirst slide surface (10) cyclically with respect to the second slidesurface (20) in a vertical direction (D) crosswise to the path (P), soas to move the first and second slide surface (10, 20) cyclicallytowards and away from each other; and the unit (1) is characterized inthat an elastic member (24 a) is interposed between the actuating device(24) and the first slide surface (10) to permit elastic self-adjustmentof the position of the first slide surface (10) in the verticaldirection (D). 28) A unit as claimed in claim 27, wherein the conveyingmeans (9) feed the containers (2) along the path (P) with anintermittent movement comprising a cyclic succession of travelling stepsand hold steps; and the actuating device (24) is timed with theconveying means (9) to keep the first and second slide surface (10, 20)close to each other during the hold steps in the intermittent movement,and to keep the first and second slide surface (10, 20) away from eachother during the travelling steps in the intermittent movement. 29) Aunit as claimed in claim 27, wherein the first and second slide surfacecomprise electric heating elements. 30) A cigarette packing linecomprising a cellophaning machine (5) for applying respectiveoverwrappings of transparent plastic material to packets (2) ofcigarettes, a cartoning machine (6) for producing cartons of packets ofcigarettes, and a feed unit (1) interposed between the cellophaningmachine (5) and the cartoning machine (6) to receive a succession ofpackets of cigarettes from an output of the cellophaning machine (5) andtransfer the succession of packets of cigarettes to an input of thecartoning machine (6); the packing line being characterized in that thefeed unit (1) is of the type claimed in claim
 1. 31) A method of feedingcontainers arranged in a number of superimposed rows; the methodcomprises the steps of: feeding the containers (2), arranged in at leasttwo superimposed rows (3, 4), along a horizontal path (P); and expellingany faulty containers (2) from the path (P) at a reject station (S2)located along the path (P); and the method is characterized bycomprising the steps of: parting two superimposed containers (2), bytranslation in a vertical direction (D) perpendicular to the path (P),at a parting station (S3) upstream from the reject station (S2);bringing two facing containers (2) back into contact with each other ata stacking station (S4) downstream from the reject station (S2); feedingthe two rows (3, 4) of containers (2), separately and facing each other,between the parting station (S3) and the stacking station (S4); and onlyexpelling from the path (P), at the reject station (S2), one container(2) in a bottom row (3) or one container (2) in a top row (4). 32) Amethod as claimed in claim 31, wherein, between the parting station (S3)and the stacking station (S4), a bottom row (3) of containers (2) ispushed along a first slide surface (10) parallel to the path (P) and forsupporting the containers (2) in sliding manner, and a top row (4) ofcontainers (2) is pushed along a second slide surface (20) parallel toand facing the first slide surface (10) and for supporting thecontainers (2) in sliding manner.